Functional responses to anthropogenic disturbance and the importance of selected traits: A study case using dung beetles

Abstract

Functional diversity has been defined as the value, range, distribution, and relative abundance of the functional traits of individuals that belong to an ecosystem. Thus, the functional response of organisms to environmental disturbances depends largely on their functional traits. Here, we evaluated dung beetle functional diversity associated to the Atlantic Forest replacement using a matrix with 25 functional traits (10 morphological, four ethological, and 11 physiological). We compared functional diversity among native and disturbed habitats with a multi and single trait approach. Contrary to previous studies, habitats with higher disturbance (open pasture) exhibited higher functional diversity compared to native forests, which could be explained by the incorporation of physiological response traits. Species of open disturbed habitats showed extreme values of such traits, explaining the observed pattern. The inclusion of several traits that represent both species ecology and morphology, and their physiology, generates different results to those observed in previous functional studies. This highlights the importance of including a large variety of functional traits in future functional diversity studies. We propose that functional traits must (1) be carefully chosen according to their biological and functional basis; (2) represent species ecology and physiology; and (3) include both effect and response traits. In addition, we consider it is extremely relevant to include a multi and single trait approach in functional diversity studies. A combination of all these considerations will provide a more realistic and complete overview of functional diversity patterns and the potential consequences of human disturbance on ecosystem functioning.